Abstract：In order to investigate the cyclic stress response behavior and low-cycle fatigue behavior of Incoloy 825 nickel-based alloy, the applied total strain amplitude controlled fatigue tests at both room temperature and 760 ℃ were carried out, and the strain fatigue parameters of the alloy at different temperatures were determined. The dislocation substructures and morphologies of fracture surfaces for the alloy after low-cycle fatigue deformation were analyzed with the transmission electron microscope(TEM)and scanning electron microscope(SEM). The results show that at room temperature, the alloy exhibits the characteristics of cyclic hardening followed by the cyclic softening, while the alloy exhibits the characteristics of cyclic hardening followed by either cyclic softening or cyclic stability at 760 ℃. The relationship between both plastic and elastic strain amplitudes as well as reversals to failure at different temperatures for the alloy shows a single slope linear behavior, which can be described by the Coffin-Manson and Basquin equations, respectively. At both room temperature and 760 ℃, the low-cycle fatigue deformation mechanism for the alloy is mainly the planar slip. In addition, the fatigue cracks initiate and propagate in the transgranular mode.